Third lecture

Our third lecture with Prof Katty was on mutation. Mutation is any inheritable change in the base sequence of DNA. It can be spontaneous (occurs without a mutagen)  or induced (chemical and physical agents to induced the mutation) .

Types of Mutations:

Base substitutions (a single base at one point in the DNA sequence is replace with a different base) There are three types under this mutation which are silent, missense, nonsense.

Frameshift mutation: insertion or deletion, shift in the reading frame

Types of mutagens: base analogues, chemical mutagen, radiation, intercalating agents.

To identify mutants, detection by selecting or testing for an altered phenotype. Two kinds which are nonselectable and selectable ( positive selection and negative selection).  

Positive (direct) selection- isolate mutants that require amino acids or other growth factors (parent cannot grow)

Negative(indirect selection)- nutritional mutant, inability to grow in agar plate lacking the nutrient (parent grow). 

Well basically this is the summary of this morning class.

 

Stormy evening

The second lecture was on regulation of gene expression. Our class was this evening, started at 3 pm because we went to NUCEL at SACC. The weather was definitely suitable for us to stay on our bed. But yeah, it was a bit stormy, and scary. Still, the class continued haha. 

Two types of modes of gene expression – Constitutive expression ( expressed at the same rate at all times) and inducible expression (in response to conditions.

Two types of regulation in cell – regulation of enzyme activity (feedback inhibition, allosteric inhibition) and regulation of enzyme synthesis ( gene expression, transcription ofmRNA – repression & induction).

Repressor blocks transcription and activator encourages transcription

For try Operon, when there is no tryptophan, the inactive repressor stay inactive, hence transcription will occur. When there is tryptophan, it will bind to the inactive repressor making it to be active. So the transcription is blocked.

For lac operon, when there is no lactose, it can’t bind to the active repressor in order to make it inactive, so the transcription process is OFF. But if there is lactose, lactose will bind to it and transcription process is ON.

Eventho it was raining outside, we managed to finish the lecture in an hour only! Well yeah, who doesn’t like class that ends early hehehe miss you Dr Wan!

Prof Katty :D

Today was our first class with Prof Datin Paduka Dr Khatijah. She will teach my class for four lectures- Microbial genetics. Our first lecture was on structure and function of genetic materials.

Genetics: is the science of heredity

Genome: genetic information in a cell

Chromosomes: structures containing DNA that carry genetic information

Genes: segments of DNA that code for functional products.

DNA – deoxyribonucleic acid. It is for storage of genetic information, self-duplication and inheritance and expression of genetic message.

RNA – ribonucleic acid

Nucleic acids- Adenine(A), Guanine(G), Cytosine(C), Thymine(T)[Uracil(U) in RNA]. The pair is AT/U(2 hydrogen bonds) and GC(3 hydrogen bonds).

Genotype is genetic composition of an organism, information that codes for all the characteristics.

Phenotype is actual expressed properties of an organism, which are observable characteristics and manifestation of genotype.

The process of producing protein from nucleic acid- DNA replication, transcription, translations. DNA replication always proceed from 5’ phosphate to 3’ hydroxyl.  It is proofreading by DNA polymerase. Transcription is synthesis of a complementary strand of RNA from a DNA template. Lastly, translation is a process in which information in the mRNA is used to dictate the amino acid sequence of a protein.

These are actually some of what we learned earlier today. The class was interesting of course. Because learning from someone who has so many experience and knowledge, we could listen to her story and became inspired. She shared some of her story, and I am looking forward to our next class!

Game equals to fun!

               So basically today, we played few games on eukaryotic topic. The games we played were – poison box(cilia, flagella, cytoplasm), roleplay(cell membrane), spin your ribosome, dart quizzes(nucleus), jumps lysosome jump, bingo(vacuole), smooth endoplasmic reticulum, wheel decide(RER), golgi penalty, and quiz oh quiz(mitochondria).

We covered the whole chapter by playing these games. What I get from today’s class was, it is not necessary for us having only formal classes. We actually need sometimes for informal classes. When I played these games, and when it came to my group to answer the question, we tried to find the answer. And from that, we get to know the answer and memorized it. We also listen to others’ answers. 

Other than that, Dr Wan asked us to make a mind map on virus topic. So this is my mindmap. That’s all :)